80 Mr. J. Napier on Copper Smelting. 



firmament over some spots of the earth's surface may be changed, 

 which would cause the rays of the sun at those places to traverse 

 a greater or less length of the firmament. I hold, that if these 

 motions are sufficiently extensive, they must produce sensible 

 alterations in the intensity of the morning and evening red. 



With regard to the action of clouds and mists in the lower 

 regions of the atmosphere in producing the morning and evening 

 red, I follow Professor Forbes and M. Clausius. I look upon 

 the clouds as white, or nearly white reflectors, which only ap- 

 pear coloured in consequence of red light falhng on them, or 

 from being seen through a coloured mist. I cannot, however, 

 come to a conclusion as to whether the usual sombre colours of 

 the clouds are generally produced in the clouds themselves or 

 in the clearer air ; neither can I see any reason why, in account- 

 ing for the colours of the clouds, we must restrict ourselves to 

 the consideration of those particles only which produce the first 

 blue and red. 



I am, Gentlemen, 



Your most obedient Servant, 



7 Prospect Place, Ball's Pond Road, Reuben PhiLLIPS. 



December 11, 1852. 



VIII. On Copper Smelting, By James Napier, F.C.S."^ 

 [Continued from vol. iv. p. 465.] 



WHEN the ore is sufficiently calcined, it is let down from 

 the hearth into the cubs or vaults beneath by openings 

 in the floor ; water is added to the hot ore in the cubs until the 

 whole is completely drenched ; during the addition of the water 

 much sulphuretted hydrogen is given ofi". The ore is then 

 removed from the cubs to a yard, and there stored up until 

 removed to the fusing-furnace. The oldest portion calcined is 

 taken first, it being of considerable importance that the ore should 

 lie for some time in the moist state after the calcining operation, 

 in order that the metals present may become partially oxidized. 

 It is found that a few days' exposure in this way not only facili- 

 tates the fusing, but produces a richer mat than if the ore were 

 fused directly from the calciner. 



An ore-fusing furnace is fitted up with a hopper upon the 

 roof, into which the workman puts the charge of calcined ore, 

 while the fusion of a preceding charge is going on. The ore is 

 weighed out to the workman in hundredweights, and carried to 

 the hoppers in boxes. The charge for an ordinary-sized fusing- 

 fumace ranges — 



* Communicated by the Author, who reserves to himself the copyright, 

 any infringement whereof will invoke legal proceedings.—EDS. 



